Conduit and cable cutter attachment for explosive actuated devices

ABSTRACT

A cutting attachment is disclosed herein for detachably connecting to a conventional explosive actuating device for severing conduit, cable, tubing, pipes, rods, or the like. The cutting attachment includes a vise grip having semi-circular opposing jaw members adapted to releasably engage and retain a length of the conduit or cable intended to be severed. The jaw members flightably mount a cutting blade arranged for reciprocal movement through slotted guides, hinged guides or the like, formed on opposite sides of the jaw members. A detachable coupler is carried on the jaw members for mounting the blade onto the explosive actuating device.

United States Patent [191 Ramey et a1.

[451 Jan. 21, 1975 Walter L. Howland, 601 8. Sunset Canyon Dr., Burbank, Calif. 91501 [22] Filed: Jan. 12, 1973 [21] Appl. No.: 323,245

[52] US. Cl 30/92, 30/241, 30/277, 30/DIG. 4 [51] Int. Cl B23d 21/10, B26d 3/16 [58] Field of Search 30/92, DIG. 4, 277, 289, 30/241 [56] References Cited UNITED STATES PATENTS 2,248,642 7/1941 Phillips 30/92 X 2,539,124 l/l951 Findlay 30/92 2,716,813 9/1955 Smyres 30/241 X 2,863,214 12/1958 Szappanyos 30/92 X 3,024,530 3/1962 Haskell et a1. 30/92 3,036,798 5/1962 Martin 30/277 X 3,142,219 7/1964 Martin 30/92 X 3,284,895 11/1966 Selander et al..... 30/908 X 3,393,605 7/1968 Parnell 30/D1G. 4

Primary ExaminerAl Lawrence Smith Assistant Examiner-J. T. Zatarga Attorney, Agent, or FirmRoger A. Marrs [57] ABSTRACT A cutting attachment is disclosed herein for detachably connecting to a conventional explosive actuating device for severing conduit, cable, tubing, pipes, rods, or the like. The cutting attachment includes a vise grip having semi-circular opposing jaw members adapted to releasably engage and retain a length of the conduit or cable intended to be severed. The jaw members flightably mount a cutting blade arranged for reciprocal movement through slotted guides, hinged guides or the like, formed on opposite sides of the jaw members. A detachable coupler is carried on the jaw members for mounting the blade onto the explosive actuating device.

6 Claims, 4 Drawing Figures CONDUIT AND CABLE CUTTER ATTACHMENT FOR EXPLOSIVE ACTUATED DEVICES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to conduit and cable cutting devices and more particularly to a novel cutting device adapted to detachably connect with a conventional explosive actuated device so that its cutting blade is operated therefrom.

2. Description of the Prior Art In a construction industry, it has been a conventional practice to cut or severe various lengths of conduit or cable by employing hack-saws, sabre saws and crosscut saws for severing or cutting the conduit or cable. The saws may be electrically operated or may be manually employed. In either event, it is difficult to cut such conduit or cable since the cable must be anchored during the procedure, chips must be collected and the cut must be straight and as clean as possible so that the cable jacket is not distorted. In the case of conduit, the wires enclosed by the jacket must be severed in such a manner that the wires do not fuse together or cause short circuits therein. Furthermore, cutting by hand is extremely cumbersome and laborious while using electrical saws rapidly deteriorates the cutting edge of the saw blade and electrical is not always available while operating the saw motor.

A convenient form of actuation in the building industry is in explosive devices such as automatic nailers and stud installation devices which employ a cartridge discharge for moving a piston against the object to be installed for imparting a driving force thereto. Although such devices have been successful in the use of installing nails and studs, such an actuator has not been employed in the cutting process for severing conduit or cable. Such a device is desirable for use since it does not require electrical power and sufficient driving force is derived from the explosive charge for moving a cutting blade.

Therefore, there has been a long standing need to provide an explosive actuated cutting blade for severing conduit and cable which takes the form of an attachment capable of releasably coupling with a conventional explosive actuating device so that the device may be used for a variety of applications with necessitating a change in its basic structure.

SUMMARY OF THE INVENTION The problems and difficulties encountered with prior devices for severing or cutting cable or conduit are obviated by the present invention which provides a novel attachment for releasably coupling with a conventional explosive actuating or driving device. The cutting attachment of the present invention provides a body capable of releasable coupling with the bell of a conventional explosive low velocity gun. Outwardly projecting from the body is a pair of jaw members wherein each jaw member is provided with a semi-circular clamping portion carried by opposing jaw members contoured to fit a portion of conduit or cable in a clamping or gripping arrangement. Each jaw member is carried by one end of a clamping device taking the form of a vise type grip including a pair of handles that are pivotally connected together by suitable hinged members. Each of the jaw members includes aligned slots at their opposite ends so as to reciprocally mount a guillotine or cutting blade. The cutting blade passes through the captured or clamped conduit or cable so as to effect separation and severing thereof. The cutting blade includes a piston adapted to be slidably received within the bore of the explosive actuating device.

A feature of the invention resides in the provision of angular jaw members defining the clamping area or space holding the conduit or cable so that when the cutting edge of the blade strikes the conduit or cable, a straight line cut is made rather than an angular cut as would be made if the conduit or cable were not bent by the contoured or shaped jaw members.

Therefore, a primary object of the present invention is to provide a portable attachment device for explosive actuated tools whereby the explosive charge may be employed for driving a cutting edge through conduit or cable.

Another object of the present invention is to provide a novel attachment device for conventional explosive actuating tools whereby a cutting blade is reciprocally mounted in the attachment for receiving the driving force from the explosive charge whereby the conduit or cable iscut.

Still another object of the present invention is to provide an inexpensive attachment for explosive actuated tools including'a means for clamping a portion of cable or conduit intended to be severed by a cutting blade actuated by the explosive discharge of the tool.

Yet another object of the present invention is to provide an attachment for conventional explosive actuated tools which inexpensive to manufacture, easy to use and that may be readily attached and detached from the bell of an explosive tool.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partly in section of the cutting attachment of the present invention illustrated in its mounted position on the barrel of a conventional explosive discharged tool;

FIG. 2 is a cross-sectional view of the jaw members of the cutting attachment as taken in the direction of arrows 22 of FIG. 1;

FIG. 3 is a transverse cross-section view taken in the direction of arrows 33 of FIG. 1;

FIG. 4 is a view similar to the view shown in FIG. 2 of another embodiment of the present invention showing a punch slidably carried by the jaws.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the novel cutting attachment device of the present invention is indicated in the general direction of arrow and it is shown attached to a barrel ll of an explosive actuated device that is of conventional design. Such an explosive actuated device not only includes barrel 11 but a pistal grip 12 forming the handle and a trigger mechanism 13 operable by the finger of the user. Within the barrel 11, there is a firing chamber indicated by numeral 14 into which an explosive cartridge is deposited by the user. Upon actuation of the trigger 13, a firing pin causes the explosive charge 15 to fire and the resultant explosive gases from the discharged cartridge enter expansion chamber 16. As the gas expands, a drive piston 17 slidably carried in the barrel 11 is forceably urged out of barrel 11 from bore 18. However, engagement of shoulder 20 with mating shoulder 21 formed in the barrel arrests movement of piston 17 from actually leaving the tool. As is the usual practice, a variety of fastening tools may be detachably coupled to the end of barrel 11 and the terminating end of piston 17 strikes whatever tool is attached at the end of the barrel.

In the present instance, an attachment device for cutting or severing conduit and cable is provided in the direction of arrow 10 which includes a base 25 detachably coupled to the end of barrel 11. Such attachment means may take the form of mating threadable engaging fastening means or other suitable detachable coupling means may be provided. Outwardly projecting from base 25, there is provided a pair of jaw members 26 and 27 which are pivotally connected together by means of a lock grip device or self-locking pliers indicated in general by the numeral 28. The lock-grip pliers are of a standard construction and jaw member 26 is permanently secured to the base 25.

The stationary jaw 26 includes a semi-cylindrical portion or cut-out and has a length which is considerably greater than the length usually provided with the lock-grip pliers; The purpose of this extra length of the stationary jaw 26 is to receive a sufficient length of an electrical flexible tubing such as cable or conduit 31, as noted in FIG. 2, to hold the portion of the tubing grip from flexing.

A palm grip portion 32 is pivotally attached to the arm 29 of the lock-grip pliers by means of a pivot 33. A moveable jaw 27 also includes a semi-circular or cylindrical portion corresponding but in opposition to the semi-circular portion 30 carried by the fixed jaw 26. The moveable jaw 27 is also of the same length as the jaw 26 as noted in FIG. 2. The moveable jaw is carried by a second handle 34 for the lock-grip pliers 28. The advantage of the lock-grip pliers resides in the fact that when the handle 34 is moved towards the handle 32 for closing the jaws 26 and 27 to grip the flexible conduit 31, the pliers are self-locking and will continue to grip the flexible conduit like a vise without the need of the operator continuing to move the handle 34 towards the handle 32. At the same time, the lock-grip pliers have a release lever 35 that is pivotally mounted at pivot 33 to handle 32. When this release lever 35 is actuated, it will release the moveable jaw 27 and permit this jaw to be swung away from the stationary jaw 26 for freeing the conduit or cable 31 from the jaws. An adjusting screw 36 is carried by the free end of the handle 34 and this screw may be adjusted for moving the jaws 26 and 27 toward or away from each other to accommodate the conduits 31 or the like of different sizes. A lock nut is mounted on adjusting screw 36 and can be tightened against the end of the handle 34 for preventing accidental rotation of the adjusting screw. Also, a pivot length 37 is pivotally connected between the link 29 and handle arm 34 to stabilize the pliers. The jaws are open in accordance with the showing in broken lines whereas in solid lines, the jaws are closed and the lockgrip pliers are locked into position about the conduit 31.

It can be seen that the lock-grip pliers hold the respective jaws 26 and 27 in alignment so that a reciprocating guillotine or cutting blade 40 may travel from its stored position on fixed jaw 26 through the cable or conduit 31 into its completed position shown in broken lines on jaw 27. Internally, each of the jaw members includes co-extensive grooves on opposite sides so as to accommodate the opposite edges of the blade. Grooves 41 and 42 are associated with fixed jaw member 26 while grooves 43 and 44 are associated with moveable jaw 27. It is to be particularly noted that a transverse groove 45 is formed in moveable jaw 27 between grooves 43 and 44 which serve as a collection groove for depris, chips or the like collected during a cutting or severing procedure.

It is to be particularly noted that the knife blade 40 includes a V-shaped cutting edge 46 and at its opposite end, blade 40 is attached to a plate 47. Plate 47 mounts a rod 48 that is slidably received into bore 18 of barrel 11. The free end of rod 48 is struck by the piston 17 when the cartridge 15 has been fired. The force of piston 17 imparted to rod 48 moves the blade 40 into and through its cutting procedure.

Referring now to FIG. 2 in detail, it can be seen that the opposing gripping surfaces of jaw members 26 and 27 are slightly curved so that the cable is placed in tension on the cutting side thereof when the clamp is in its locking condition. This provides a sharp, clean and straight cut when the blade 40 severes the conduit or cable. Also, it is noted that the blanks of the'opposing jaws are substantially adjacent the conduit or cable 31 so that the cable can be suitably bent to provide the proper tension during the cutting procedure.

In FIG. 3, it is more clearly shown that blade 40 travelled in opposing grooves 41 and 42 so that the blade reciprocates therein. The blade never leaves the grooves since the rod 48 is captured within its bore by body 25.

Another embodiment of the present invention is shown in FIG. 4 wherein the blade 40 has been replaced by a punch 50 that reciprocates within the fixed jaw 26 prime. The punch 50 is mounted on a plate 51 that rides in grooves 41 prime and 42 prime in a manner similar to that previously described with respect to blade 40. Fixed jaw 26 prime and moveable jaw 27 prime are joined by the lock-grip pliers as previously described and the moveable jaw 27 prime includes a receptacle 52 adapted to receive the tapered end of the punch 50. Also, the receptacle will receive the depris for storage generated during the punching operation. In this instance, the punch will form a hole or aperture in the cable or conduit placed between the moveable and fixed jaw.

- In view of the foregoing, it can be seen that the cutting attachment device of the present invention may be readily coupled to any existing explosive actuating tool. The conduit or cable to be severed is placed between the opposing semi-circular portions of the fixed and moveable jaw members and the lock-grip device 28 is actuated to secure the jaws in place. Next, the cartridge 15 is fired and the expanding gases produced thereby urges the piston 17 to strike the end of rod 48 so as to impart a driving force thereto that causes blade 40 to move from the fixed jaw to the moveable jaw. During this procedure, blade 46 cuts through the conduit or cable 31 and the blade 40 is guided by the opposite groove slots formed in the respective jaw members.

The mating and corresponding curved surfaces of the jaw members as shown in FIG. 2 provide a saddle for bending the conduit or cable 31 so that the portion to be severed is in tension. Any debris or chips will be located within the bottom of groove 45 after the cutting procedure. When the lock-grip pliers are released, jaw members 26 and 27 will open to release the ends of the severed cable or conduit.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

l. A cutting attachment in combination with an explosive actuated device having a central bore formed in an elongated barrel for slidably mounting a piston movably responsive to expansion gases of an explosive discharge, said cutting attachment comprising:

a cylindrical body having an open-ended passageway extending therethrough;

means releasably coupling said body to said barrel whereby said passageway and said bore are coextensive;

a pair of jaw members movable with respect to each other for gripping an article to be severed therebetween;

one jaw member of said pair fixedly secured to said cylindrical body;

a cutting blade movably mounted on said jaw members for reciprocal movement passed said article to be severed in response to movement of said piston through said bore; and

handles secured to said movable jaw member and to said fixed jaw member and links pivotably interconnected between said handles constituting a releasable lock-grip vise for holding said article to be severed.

2. The invention as defined in claim 1 wherein:

each of said jaw members includes a semi-circular portion for gripping opposite sides of said article to be severed.

3. The invention as defined in claim 2 wherein:

said jaw members include mated opposing arcuate surfaces engagable with said article to be severed for placing tension forces therein to bend said article whereby a substantially straight cut is made to sever said article 4. The invention as defined in claim 3 wherein:

said cutting blade includes a rearwardly extending rod insertably disposed in said bore so as to be struck by said piston in response to expansion of said explosive gases.

5. The invention as defined in claim 4 wherein:

said body includes a passageway for slidably mounting said cutting blade rod and said passageway is coextensive with said barrel bore.

6. The invention as defined in claim 5 wherein:

each of said jaw members includes opposing and coextensive slots for slidably mounting said cutting blade. 

1. A cutting attachment in combination with an explosive actuated device having a central bore formed in an elongated barrel for slidably mounting a piston movably responsive to expansion gases of an explosive dischArge, said cutting attachment comprising: a cylindrical body having an open-ended passageway extending therethrough; means releasably coupling said body to said barrel whereby said passageway and said bore are co-extensive; a pair of jaw members movable with respect to each other for gripping an article to be severed therebetween; one jaw member of said pair fixedly secured to said cylindrical body; a cutting blade movably mounted on said jaw members for reciprocal movement passed said article to be severed in response to movement of said piston through said bore; and handles secured to said movable jaw member and to said fixed jaw member and links pivotably interconnected between said handles constituting a releasable lock-grip vise for holding said article to be severed.
 2. The invention as defined in claim 1 wherein: each of said jaw members includes a semi-circular portion for gripping opposite sides of said article to be severed.
 3. The invention as defined in claim 2 wherein: said jaw members include mated opposing arcuate surfaces engagable with said article to be severed for placing tension forces therein to bend said article whereby a substantially straight cut is made to sever said article.
 4. The invention as defined in claim 3 wherein: said cutting blade includes a rearwardly extending rod insertably disposed in said bore so as to be struck by said piston in response to expansion of said explosive gases.
 5. The invention as defined in claim 4 wherein: said body includes a passageway for slidably mounting said cutting blade rod and said passageway is coextensive with said barrel bore.
 6. The invention as defined in claim 5 wherein: each of said jaw members includes opposing and co-extensive slots for slidably mounting said cutting blade. 